A facile [hydroxy(tosyloxy)iodo]benzene mediated synthesis of 2-arylimidazo[1,2-a]pyrimidines and their conversion into 3-bromo-2-arylimidazo [1,2-a]pyrimidines

摘要

alpha-Tosyloxyketone 2,obtained through hypervalent iodine oxidation of enolizable ketones using [hydroxy(tosyloxy)iodo]benzene (HTIB) in acetonitrile,on treatment with 2-aminopyrimidine 3 generates regioselectively 2-arylimidazo[1,2-a]pyrimidine 6 which upon subsequent treatment with bromine undergoes electrophilic substitution at position-3 to yield 3-bromo-2-arylimidazo[1,2-a]pyrimidine 8.